Lagarfljot

Lagarfljot runs about 25 kilometres south-west from Egilsstadir, deep and narrow, and its water is grey with glacial silt, which keeps light from penetrating far and means the lake has little visible life below the surface. It has been home in folklore to the Lagarfljotsormur, a serpent recorded in Icelandic annals as far back as the fourteenth century and reported sporadically since; the sightings are usually explained as gas-lifted vegetation mats or wave effects. Since the Karahnjukar hydroelectric scheme was completed in 2007, more glacial water has been routed into the system, and the silt load and water level have changed as a result, which has been argued over locally ever since.

What you actually see

• A long narrow lake - about 25 kilometres, and deep for its width.
• Grey glacial water - silt that blocks light and hides the bottom.
• A serpent in the annals - reported since the fourteenth century.
• A changed river system - more glacial water since the 2007 hydro scheme.

When to go

June to September. Half a day driving the shores.

Honest expectations

The water is opaque grey rather than scenic blue, which surprises people. There is no swimming or clear-water boating here. The shore roads are partly gravel. Weather in the east is often better than the coast, but not reliably.

Nearby

Hallormsstadur forest lines the eastern shore; Hengifoss is at the far end.